Analytical Sciences

Abstract − Analytical Sciences, 23(5), 569 (2007).

Electrochemical Determination of Trace Promethazine Hydrochloride by a Pretreated Glassy Carbon Electrode Modified with DNA
Zhou-Sheng YANG, Jun ZHAO, Da-Peng ZHANG, and Yun-Chun LIU
College of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu 241000, P. R. China
A highly sensitive electrochemical biosensor for the detection of trace amounts of promethazine has been designed. Double stranded (ds)DNA molecules are immobilized onto a pretreated glassy carbon electrode (GCE(ox)) surface. The voltammetric behaviors of promethazine on DNA-modified electrode were explored by means of cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The promethazine gave rise to a pair of well-defined peaks, which appeared at Epc = 52 mV and Epa = 96 mV (vs. Ag/AgCl) in 0.10 M acetate buffer (pH 5.0). The peak current was linearly enhanced with increasing the concentration of promethazine. The calibration was linear for promethazine over the range of 4.7 × 10-10 to 9.3 × 10-9 M with a correlation coefficient of 0.999. The limit of detection (LODs) was 3.0 × 10-10 M (S/N = 3). The modified electrode was applied to determine promethazine in human blood samples with satisfactory results.